This invention relates to the design of a microwave oven for a motor vehicle, the oven being configured and adapted to fit into the dashboard area, and, in one aspect, into the space traditionally reserved for the glove compartment, the oven also providing glove compartment storage space within an insertable cassette which is removed to allow microwave heating.
A variety of mechanical and electro-mechanical patents demonstrate space-saving modifications and multiple usage features in the design of microwave ovens, while other patents focus on the provision of regulated electric power and control features needed in adapting microwave oven technology to motorized vehicles including automobiles, boats and the like. For example, Buske et al., U.S. Pat. No. 5,235,150 describe a two-part space-saving microwave oven including a compact microwave-producing deck portion, and a removable (storable) chamber cover. Smith et al., U.S. Pat. No. 4,481,395 describe a volume-restricting insertable heating compartment for the microwave oven which functions to limit the volume of food being heated at any time. Eke, U.S. Pat. No. 4,508,947 describes a portable microwave oven which provides thermal as well as microwave energy, and an air fan and food turntable to optimize the cooking uniformity and quality of the oven. Sherer et al, U.S. Pat. No. 5,369,255 describe a combined microwave oven and food carrier which can be powered by a motor vehicle battery. Directly and remotely controlled door lock and safety interlock electrical switches applicable to safe operation of microwave ovens are described by Takayama et al., U.S. Pat. No. 3,823,294, by Schuchert, U.S. Pat. No. 4,201,901, by Nishikawa, U.S. Pat. No. 4,935,593, by Shimizu et al. in U.S. Pat. No. 4,450,335, and by Ishikawa et al., U.S. Pat. No. 3,700,846. A number of other patents have focussed on methods and designs for improving the AC and/or DC power supplies, and control functions for microwave ovens in motorized vehicles. Nakabayashi et al., U.S. Pat. No. 5,347,109 describe a vehicular DC power source, an inverter, a magnetron, and a feedback circuit for controlling the inverter output based upon measurement of the DC output. Low et al., U.S. Pat. Nos. 4,904,837 and 5,276,300 describe microwave ovens for transports such as vehicles, in which the oven may be powered either by either AC current, or by DC current through an inverter, and the resultant AC power is delivered through a door interlock safety switch to a high voltage transformer, and then to a magnetron. Sakurai et al., U.S. Pat. No. 4,667,075 describe a microwave oven for vehicles in which the electrical alternator of a vehicle generates three phase AC voltage which is supplied to a transformer, whose secondary connects to rectifying diodes whose output in turn, powers the positive terminal of the magnetron which is connected in turn, via its heater and negative terminals to the positive and negative battery terminals respectively.
Applicant has found very little prior art relating to the placement of a microwave oven within a vehicle, oven door design geometry, oven door movement relating to use within a motor vehicle, or multiple uses for a space occupied by a microwave oven in a motor vehicle. Nahabayashi et al., U.S. Pat. No. 5,347,109, show a microwave oven located in the motor vehicle console area, a storage area located between the two front seats of the automobile. Their patent indicates that the oven is not constrained to this location. However, the patent of Nahabayashi et al. shows only a conventional front-access microwave oven door, and when the oven is placed between the two front seats, access to the oven chamber appears awkward at best. Unfortunately, it would not be possible to remedy their access problem by simply rotating the oven of Nahabayashi et al., and mounting it with its door opening upward. Among other reasons, the containers for "fluid food" as shown in the mounted container supports of Nahabayashi et al. would immediately spill their fluid contents. In other prior art, Schuchert, U.S. Pat. No. 4,201,901 shows a drop-down bottom-hinged door which, when opened, activates a safety interlock switch which interrupts electrical power in a conventional microwave oven. Door movement is controlled by spring-tensioned counterbalance arms which contact and control safety interlock power switches. There is no suggestion that the drop-down door is adaptable for use in a motor vehicle, or adaptable by further modification for holding hot beverages and other foods. In a prior art reference unrelated to microwave ovens, and related only to chilled glove compartments, Zorn, U.S. Pat. No. 5,099,649 describe a Peltier-type refrigeration element placed in a flexible insulated bag which, in turn, is placed inside a vehicle glove compartment. The device is constructed so that when refrigeration is not needed, the bag may be collapsed within the glove compartment, and the compartment used for storage. However, re-deploying the refrigerated bag requires that items stored on top of the collapsed insulated bag be relocated before the insulated bag could be used again.